Exactly! They're both concatenative languages, or at least languages which have a concatenative subset. Juxtaposition is composition. APL/K and Forth also have

Exactly! They're both concatenative languages, or at least languages which have a concatenative subset. Juxtaposition is composition. APL/K and Forth also have very concise syntax for declaring functions. // JS const foo = (x,y) => 1 + x * y // K, lambda with implicit arguments foo: {1+x*y} // K, points-free foo: 1+* // Forth : foo * 1+ ; It's subtle, but I think making function declarations "lightweight" in this manner is important for encouraging factoring. In APLs the scale of the semantic units you give names to is a little different, but that's its own separate discussion.